CSS

Notes

ID's are unique.
- Each element can have only one ID.
- Each page can have only one element with that ID.
Classes are NOT unique.
- You can use the same class on multiple elements.
- You can use multiple classes on the same element.
The DOM is just a tree of objects. CSS selects parts of that tree and applies attributes to those objects. It's all just code, it's just a shorthand for adding a bunch of attributes to a bunch of objects.
Always design your CSS format from the inside out
- format the elements within their container so that they look correct regardless of the size of the container.
- similarly format those containers within their own containers
- repeat until <body> is the containers
- never use absolute widths (px, in, cm, etc.) for anything
body tag takes up the whole width and height of the browser screen.